Seeing (and Hearing) Is Believing

Over the last few years, there has been confusion over which laws or codes apply to the audible and visible notification appliances. The confusion has been so great that there are some fire officials who believe it is their duty to enforce the requirements of a law that does not grant them the authority.

The law I am referring to is the Americans with Disabilities Act (ADA). When this law was enacted in 1990, the requirements for visible appliances (strobes) were defined but not developed based on research.

These requirements forced manufacturers of strobes to react quickly to meet them, resulting in a strobe that did not have the same compliance with the National Fire Alarm Code, National Fire Protection Association (NFPA) 72. This strobe was labeled as a 15/75 candela unit with the 75 candela portion designed to comply with the ADA. The intensity of the 75 candela strobe was only observed when looking at the strobe directly. If viewed from either side, the intensity dropped off considerably.

Underwriters Laboratories (UL) performed research using hearing-impaired people to determine what candela intensity was appropriate for direct and indirect viewing. This research resulted in the development of a new UL standard, UL 1971, Visual Signaling Appliances.

Three years after Congress passed the law establishing the ADA, the technical committee for the NFPA 72 chapter entitled, “Notification Appliances for Fire Alarm Systems” used the UL research to develop the first requirements for visible appliance locations in NFPA 72-1993.

Since that time, contractors have often encountered the problem of the local fire official or the unknowledgeable designer requiring 75 candela strobes everywhere throughout the building rather than following the requirements of the code. This raises the costs for the owners being served by the contractor. Part of the problem stemmed from how the ADA was enacted. Congress required that the Department of Justice (DOJ) be the enforcing arm of the act and specifically stated that local authorities did not have jurisdiction or enforcement authority for the ADA’s requirements.

The NFPA staff began in the early 1990s to work with the DOJ to have the ADA Accessibility Guidelines—the DOJ’s enforcement guide—to allow the use of NFPA 72 requirements as “equivalent facilitation” for meeting the ADA fire alarm system audibility and visibility requirements.

After numerous hearings and false starts, the recently issued revised act contains “advisories” that reference standards accepted as providing the information necessary to comply with the ADA.

ADA Section 5, paragraph 105.2.5 states that Chapter 13, article 702.1, and Chapter 69, article 809.5.2, are governed by NFPA 72-1999 and NFPA 72-2002. The advisory to this section now states, “NFPA 72-1999 and NFPA 72-2002 address the application, installation, performance and maintenance of protective signaling systems and their components. The NFPA incorporates Underwriters Laboratories UL 1971 by reference.”

There are two required modifications of the NFPA 72 documents that are referenced. The ADA states that the standards (NFPA 72-1999 and 2002 editions) specify the characteristics of audible alarms, such as placement and sound levels. However, Chapter 13 (of the ADA) article 702 limits the volume to 110 dBA rather than the 120 dBA permitted by NFPA 72-1999.

The other change for using NFPA 72 documents for ADA compliance is Chapter 13, article 702 that requires that “visual alarm appliances be permanently installed.”

Now, any jurisdiction that has adopted a building code that references either NFPA 72-1999 or NFPA 72-2002 can avoid conflicts with past ADA requirements and simply follow the requirement of the code.

NFPA 72 requires that audible “public mode” signals be “clearly heard” and that they produce a sound level of at least “15 dB above the average ambient sound level or 5 dB above the maximum sound level having a duration of at least 60 seconds, whichever is greater, measured 1.5 m (5 ft) above the floor in the occupiable area, using the A-weighted scale (dBA).”

Public mode visible signaling is contained in Section 7.5 of the code and contains the requirements for the location and spacing of both wall- and ceiling- mounted visible notification appliances in corridors and rooms. The concern of individuals responding adversely to flashing strobes and suffering from seizures is addressed by the requirement that when there are more than two visible notification appliances in the same room or adjacent space within the field of view they must flash in synchronization.

NFPA 72 also has tables that specify the intensity of the strobe based on the space where it will be placed. It is no longer acceptable to use all one value of strobe intensity to ensure code compliance.

By following NFPA 72-2002, the contractor and the fire alarm system designer can be assured that there will be no surprises at the end of the project. EC

MOORE, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a co-editor of the current National Fire Alarm Code Handbook. Moore is a principal with Hughes Associates Inc. at the Warwick, R.I., office.